Wash-over spear apparatus



Oct. 24, 1961 F. L. LE BUS, SR 3,005,506

WASH-OVER SPEAR APPARATUS Filed Nov. 5, 1958 3 Sheets-Sheet 1 INVENTOR. FL. L'eBus 5/:

Oct. 24, 1961 F. L. LE'BUS, SR 3,005,505

WASH-OVER SPEAR APPARATUS Filed Nov. 5, 1958 5 Sheets-Sheet 2 Fig. /2

INVENTOR.

F./0 9 ATTORNEY I Oct. 24, 1961 F. 1.. LEBUS, SR 3,005,506

WASH-OVER SPEAR APPARATUS Filed Nov. 3, 1958 5 Sheets-Sheet 5 Fig/4 INVENTOR.

FL. LeBus 5n United States Patent "ice 3,005,506 WASH-OVER SPEAR APPARATUS Franklin L. Le Bus, Sn, R0. Box 2352, Longview, Tex. Filed Nov. 3, 1958, Ser. No. 771,500 9 Claims. (Cl. 175-315) This invention relates to improvements in fishing tools and more particularly, but not by way of limitation, to a fishing tool apparatus for the catching of loosened pipe or drill collars that have become stuck in an off bottom position in the well bore.

In the drilling of wells by the rotary drilling method, and particularly deep oil wells, the well bore frequently deviates from the true vertical. Such deviations are ordinarily caused by the drill bit contacting slanting geological structures and being forced from its true vertical course. When drilling a deep oil well by the rotary method, the drill bit is secured to the lower end of one or more'drill collars and the drill collars are in turn suspended from a long string of drill pipe. The drill collars are tubular members, usually approximately thirty feet in length, and are substantially heavier and more rigid than the regular drill pipe. In the event the drill bit is forced from a true vertical direction during the drilling operation, the drill collars will contact the side of the well bore and tend to remain in a Vertical position. When this occurs, continued rotation of the drilling string will cause the drill collars to rub the side of the well bore and form a smaller bore in the earth slightly off-set from the well bore formed by the drill bit. These ofi-set bores formed by the drill collars are commonly known as key seats.

When a drill bit is being removed from a well bore containing one of these key seats, the bit frequently becomes lodged therein to prevent immediate removal of the complete drilling string from the well bore. The usual practice, when such a condition occurs, is to disjoint the drill pipe and a portion of the drill collars for removal from the well bore, leaving the drill bit and one or more drill collars lodged in the key seat. In some instances, the drill pipe or collars may become broken oif and stuck oil? the bottom of the bore. Under either 0on dition, it is customary for retrieving the lodged pipe to wash over and around the stuck portion of the pipe by the use of a wash-over pipe carrying a spear apparatus engageable with the upper end of the stuck pipe so that upon a loosening of the stuck pipe, the spear apparatus will be engaged with the wash-over pipe and prevent the loosened pipe from falling to the bottom and subsequently pulled out of the well bore. Furthermore, the wash-over spear unit includes an unlatching mechanism providing disconnection of the retrieving tool from the stuck fish after it has been engaged therewith to permit removal of the retrieving tool and the wash-over pipe for any purpose, such as a replacement of the reaming shoe on the Wash-over pipe without the necessity of having to re-engage the retrieving tool with the stuck pipe.

In fishing tools of this type, it is usually necessary to provide additional sections of drill pipe to the drilling string in order to continue the downward rotation and reaming of the wash-over pipe around the fish stuck in the well bore. In adding extra sections, it is necessary to move the wash-over pipe vertically upward and where the retrieving tool is stationary with the stuck fish, such upward movement will usually cause a simultaneous vertical upward movement of the locking slips with the tapered faces of the operating bushing, thereby relocking the slips of the retrieving tool with the wash-over pipe.-

Consequently, during this upward movement of the washover pipe, it is necessary to maintain the slips in released 7 Patented Oct. 24, 1961 condition, or preclude any operation thereof during a vertical upward movement of the wash-over pipe.

This invention is generally concerned with a fishing tool apparatus having a wash-over pipe and reamer in which is disposed a spear retrieving tool in firm engagement therewith to permit a positive threading engagement of the retrieving tool with the stuck fish during amake up of the complete wash-over tool and retrieving tool. Further, the fishing tool provides for a released condition of the wash-over pipe with the retrieving tool after a make up of the tool with the stuck fish to permit a downward rotation and reaming of the was -over pipe and to maintain the wash-over pipe in the released condition to permit vertical movement of the wash-over pipe without any reengag-ernent of the tool with the wash-over pipe during this operation. However, the complete free wheeling movement of the wash-over pipe may be accomplished by a rotation in one direction to actuate a rolling cam lock mechanism to maintain the released condition of the retrieving tool with the wash-over pipe. In the initial operation, the retrieving tool is lowered with the washover pipe into the well bore for engagement with the stuck fish, after which the locking slips are placed in a released condition to permit a continued downward movement of the wash-over pipe and reamer for clearing the well bore of the stuck fish therein. When it is desired to release the complete unit for any purpose that would necessitate the retrieving tool or the wash-over pipe being removed from the well bore without necessarily disconnecting the stuck fish. The unlatching mechanism, by a lift-up of the wash-over pipe and a left hand rotation, will permit such removal, with a subsequent replacement by a reverse operation thereof.

It is an important object of the present invention to provide a spear unit adapted to cooperate with a washover pipe for retrieving stuck pipe wherein the spear unit may be alternately engaged or released with the wash-over pipe so that engagement will permit movement of the spear unit with the wash-over pipe, or in disengagement will permit movement of the wash-over pipe relative to the spear unit, thus providing vertical movement of the wash-over pipe if desired after connection of the spear unit with the stuck pipe, but leaving the spear unit in a position to engage the wash-over pipe inthe event the stuck fish should become loosened and drop in the well bore.

A further object of this invention is to provide a well tool having a spear apparatus adapted to be supported in a wash-over pipe for rotation with the wash-over pipe in the well bore, and capable of engagement with a fish lodged in the bore, yet permitting continued downward movement and rotation of the wash-over pipe after engagernent of the spear apparatus with the lodged fish.

Another object of this inveniton is to provide an improved retrieving tool for recovery of lodged drill collars in a well bore by catching the drill collars when they become dislodged from the bore.

And still another object of this invention is to provide a wash-over apparatus having a retrieving spear unit for retrieving stuck drill collars in a well bore and capable of releasable disconnection from the wash-over pipe to permit downward movement thereof, and subject to rotation of the wash-over pipe in one direction to permit independent vertical movement of the was -over pipe relative to the spear unit for maintaining the releasable disconnection hetween the spear unit and the wash-over pipe so that additional sections of pipe string may be added to the wash-over pipe for a continued washing operation.

Still another object of this invention is to provide a well tool adapted to be alternately anchored and released relative to a wash-over pipe disposed in a well bore, and

utilizing an application of hydraulic pressure in a manner to maintain the tool in a released position relative to the wash-over pipe.

And still another object of this invention is to provide a wash-ever tool apparatus for retrieving stuck drill collars in va well bore having .a spear unit engaging the stuck fish in the well bore wherein said spear unit is normally anchored to the wash-over pipe for rotation therewith, yet may be releasably disconnected therefrom so that independent vertical movement of the wash-over pipe relative to the spear unit may be obtained and thereby providing variable movements or complete removal of the Wash-over pipe leaving the spear unit engaged with he fish- And still another object of this invention is to provide a fishing tool apparatus for retrieving stuck drill collars stuck off the bottom of the well bore adapted to be alternately anchored and released relative to a wash-over pipe disposed in the bore and provided with an unlatching mechanism which will permit removal of the retrieving tool and the wash-over pipe from the well here after a connection ofthe retrieving tool with the stuck drill collar.

And still another object of this invention is to provide a wash-over tool apparatus for retrieving stuck drill collars in a well bore having an unlatching mechanism permitting removal of the retrieving tool and wash-over pipe at any stage of the wash-over operation in order to provide for a progressive removal of any washed over drill collar.

And still another object of this invention is to provide a wash-over tool apparatus for retrieving stuck drill collars in a well bore which permits a tighter gripping engagement between the tool and the wash over pipe when it is desired to back off the tool for any purpose by merely lifting up the tool and rotating the tool in any direction.

And still another object of this invention is to provide a fishing tool apparatus for retrieving drill collars stuck off bottom of a well bore including a spear unit alternately anchored and released relative to a wash-over pipe and reamer and engageable with the stuck collars in a released position to permit continued reaming of the washover pipe and reamer and provided with a rolling cam lock responsive to rotation of the wash-over pipe in one direction to maintain the spear unit in released position with the wash-over pipe.

And still another object of this invention is to provide a fishing tool apparatus for retrieving drill collars stuck off bottom of a well bore wherein the retrieving spear unit may be easily assembled and disassembled for replacement of the various elements thereof due to wear and necessity of larger sizes.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate my invention.

In the drawings:

FIGURE 1 is a vertical broken elevational view partly in section illustrating the upper portion of the retrieving tool prior to i nsertion in the wash-over pipe.

FIGURE 1A is a lower extension of FIG. 1 showing the unlatching mechanism,

FIGURE 2 is a view taken on lines 22 of FIG. 1A.

FIGURE 3 is a view taken on lines 33 of FIG.

FIGURE 4 is a view taken on lines 4- 4 of FIG.

FIGURE 5 is a view taken on lines '5--5 of FIG.

FIGURE 6 is a view taken on lines 66 of FIG.

FIGURE 7 is a view taken on lines 77 of FIG.

FIGURE 8 is a View taken on lines 8-8 of FIG.

FIGURE 9 is a view taken on lines 99 of FIG. 1A.

FIGURE 10 is an elevational view with certain parts in section for clarity showing the retrieving tool an chored in the wash-over pipe.

FIGURE 11 is a view similar to FIG. 10 showing the retrieving tool and unlatching mechanism with the slips 4 in engaging position with the wash-over pipe ready for a make up connection with the lost fish.

FIGURE 12 is a view similar to FIG. 11 showing the retrieving tool in the wash-over pipe and made up in the stuck fish and the reaming operation in progress.

FIGURE 13 is a view similar to FIG. 12 with the unlatching mechanism broken away in elevation for depiction in dotted lines of the male and female splines therein. 7

FIGURE 14 is a view similar to FIG. 12. showing the slips non-engaged, and the retrieving tool made up with the drill string in the top thereof for lowering the tool in the wash-over pipe for re-anchoring.

FIGURE 15 is a detail View of one of the flow restriction members.

FIGURE 16 is a plan view thereof.

Referring to the drawings in detail, and more particularly FIGS. 1 to 9, inclusive, reference character 1 indicates generally a retrieving tool apparatus having an upper sub member 2 provided with upper threads 3 for connection to the drill string or the like (not shown). The lower portion of the sub 2 is threadedly connected at 4 to a tubular mandrel 5 extending downwardly therefrom and its lower end is threadedly connected at 6 with a lowermost circulating sub member 7. The outer peeriphery of the mandrel 5 is provided with an outwardly extending flange or boss 8 and immediately below the boss, the mandrel is provided with a plurality of left hand threads 9 cooperating with a complementary threaded bushing 10 for a purpose as will be hereinafter set forth. The mandrel is provided with a plurality of circumferentialiy spaced axial slots or key ways 11 (FIG. 5).

An upper sleeve 12 is slidably disposed on the upper portion of the mandrel 5 and the sleeve is cut away or recessed at 13 for receiving a plurality of sectional flow restriction members 14 (FIGS. 15 and 16) maintained in vertical spaced relationship by an upper spacer ring 15 and intermediate tapered spacer rings \16. The upper end of the sleeve 12 is threaded at 17 for reception of a hold down nut 18 maintaining the How restriction members on the sleeve 12 between the nut 18 and a shoulder 19 provided by the recess 13. The slidable sleeve 12 is provided with a plurality of cut out portions or windows 29, each of which is adapted to receive afriction block 21 therein. The inner periphery of the friction blocks are provided with a plurality of pockets.

22 in which are disposed helical spring members 23 anchored at one end in the pockets 2;, and at the opposite end against the sleeve 12 for providing an outward thrust on the friction blocks 21. The blocksare secured to the sleeve 12 at the upper and lower portions by screws 24. l i

The lowermost portion of the sleeve 12 (FIG. 1) is provided with suitable threads 25 to which is threadedly secured a lower sleeve 26 slidable on the mandrel 5 with the upper sleeve A locking screw 25a extends through the sleeve 26 at the threaded portion 25 for precluding an accidental unthreading of the joint, as is well known. The sleeve 26 is recessed or cut away at 27 to provide a shoulder portion 28 around which is disposed a slip cage 29. The outer periphery of the sleeve 26 is provided with a plurality of circumferentially spaced cut out portions or recesses 30, and in each recess a spring urged latch 31 is provided (FIG. 6). The latches 31 are held in the recesses by screws 32. Suitable helical springs 33 are secured in pockets 34 provided on the inner face of the latches 31 to maintain the outward thrust of the latches for a purpose as will be hereinafter set forth.

The sleeve 26 in proximity of the threaded connection 25 is cut out to provide a recess 36 (FIG. 5) for receiving an elongated rolling cam lock member 37. The recess 36 extends into a narrower recess portion 38 having a flat wall 39 against which is disposed a spring 40 secured to the sleeve 26 by the screw The spring 4Q is provided with an arcuate end portion, 42 disposed adjacent the outer periphery of the arcuately shaped cam lock member 37. The member 37 is held in the recess 36 by a floating pin or stud 43 provided in the sleeve 26. The cam lock 37 at one end is provided with a pointed boss member 44 adapted to cooperate with one of the longitudinal key ways 11 as will be hereinafter set forth. The inner face of the cam lock 37 is provided with a plurality of serrations or teeth 45 for engagement with the outer periphery of the mandrel 5 as will be hereinafter set forth. The cam lock 37 is provided with an arcuately shaped slot 46 cut vertically through the lock for receiving the pin 43. From FIG. 5, the slot 46 is shown slightly off-set with respect to the axial center of the tubular mandrel 5 and sleeve 26, such as the oif-set center 47 relative to the center 48, so that in operation, the pin 43 may move the cam lock 37 in a wedging or cam action, thereby thrusting the teeth 45 into engagement with the outer periphery of the mandrel as will be here inafter set forth.

The bushing on the lower end of the mandrel is provided with a plurality of inwardly tapered faces 50 adapted to cooperate with the slips 51. The upper end of the bushing 10 is provided with a key way 56 (FIG. 7) for a purpose as will be hereinafter set forth. The slidable slip cage 29 disposed around the mandrel 5 is counter-bored or under-cut at 53 to leave an annulus 54 between the outer periphery of the sleeve 26 and the slip cage 29, thereby providing suflicient space for telescopically receiving the lower end of the sleeve 26. A plurality of circumferentially spaced slots 55 are provided in the upper end of the slip cage 29, and the top face of the slots 55 is provided with a plurality of notches or grooves 56 in axial alignment with and adapted to cooperate with the latches 31 as will be hereinafter set forth. The slots 55 are provided with a downwardly sloping or tapered face 57.

The slip cage 29 is cut away to provide a plurality of circumferentially spaced windows 58 into which are disposed the slips 51. One of the windows 58 is provided with a key way 59 (FIG. 7), and a key 60' secured therein by suitable screws 61. The outer faces of the slips 51 are provided with a plurality of teeth or serrations 63 toprovide locking engagement with the wash-over pipe as will be hereinafter set forth. A semi-circular recess 64 is cut into the upper end of each of the slips 51 for assisting in holding the slips in the windows 58 underneath the screw head 61. The lower end of each of the slips 51 is cut away at 65 to provide for a lower extension 66 having a plurality of recesses or pockets 67 therein. A spring :68 is disposed in each pocket 67 and has one end anchored therein and its opposite end anchored against the inner face of the slip cage 29. The slip extension 66 tests on an inwardly directed shoulder 69 of the cage 29.

A plurality of circumferentially spacedapertures 70 are provided in the circulating sub member 7 to permit limited fluid circulation through the tool to be discharged therefrom for a purpose as will be hereinafter set forth. The sub 7 is provided with male threads 71 acting as a pin member adapted to be threaded into the female box 90 of an unlatching unit generally indicated at 91. The unlatching unit 91 comprises an upper housing 92 (FIG. 1A) cooperating with a lower housing 93 wherein the lower housing has a reduced portion providing an inwardly directed shoulder 94 from which an upwardly extending mandrel 95 of smaller diameter than the lower housing 93 is provided. The lower end of the housing 93 is provided with a tapered pin member 96 adapted for connection with a threaded box of a stuck fish or drill collar 97 (FIG. 11).

The inner mandrel 95- is provided with a plurality of circumferentially spaced partially elongated flange members generally indicated at 100*. It will be apparent that a pair of diametrically opposed flange members 100 are provided on the outer periphery of the mandrel 95. However, for purposes of clarity, only one will be described. An elongated upper flange portion 101 extends axially downward and is connected with a tapered upper surface 102 of a lower body portion 103 having a lower pocket or recess 104 of substantially rectangular configuration. At the opposite side from the flange 101, a flange or lug 105 is provided on the inner housing 95 which extends upwardly from the recess 104 into integral connection with a cross flange 106 having a tapered upper surface 107. In spaced relation to the flange 105, the cross flange .106 is provided with a downwardly extending flange 108. The particular configuration of these flanges or splines 100 provides for an axial recess or groove 109 which in turn communicates through a passageway 110 with an axially disposed pocket or recess 111 provided in the cross lug 106 and in alignment with the lower pocket 104. It will be apparent that the recesses 109, 110 and 111 provide a J-slot for receiving the lug 112 therein.

The inner periphery of the outer housing 92 is provided with a pair of diametrically opposed lugs or male splines 112 and 113 (FIG. 9) which cooperate with the female splines on the inner mandrel 95 as will be hereinafter set forth. The unlatching means 91 is connected to the pin member 71 of the retrieving tool and may be utilized for removing the wash-over pipe and retrieving tool but of the well bore when it is desired to replace a reaming shoe normally attached to the wash-over pipe, as will be hereinafter set forth, or for any other purpose that would necessitate the retrieving tool or wash-over pipe being removed from the well bore without necessarily disconnecting the unlatching unit from the stuck fish 97.

In the makeup of the retrieving tool in the washover pipe 80 (FIG. 10), the tool is placed Within the wash-over pipe so that the lower end or pin portion 71 will usually extend from the end of the section of washover pipe within which it is to be engaged in order to receive the unlatching mechanism 91. The bore of the sub 7 is provided with four circumferentially spaced longitudinally extending grooves 73 for receiving any substantially square shaped wrench 74, such as shown in FIG. 2, for a purpose as will be hereinafter set forth. The upper sub member 2 and the lower sub member .7, after being made up on the upper and lower ends of the mandrel 5, respectively, are prevented from further rotation by substantially similar locking means comprising a locking stud 75 (FIG. 3) adapted to be disposed in an aligned bore 76 between the sub 2 and the mandrel 5 and held in the aligned bore or key way 76 by a locking stud 77. It will be apparent that the type of locking means for both the upper sub 2 and the lower sub 7 are the same for a purpose as will be hereinafter set forth. It will be apparent that after the retrieving tool is made up within the wash-over pipe 80, the unlatching mechanism 91 can be threadedly engaged on the pin 71 of the tool 1 for connection therewith.

Retrieving tool setting operation In order to set the retrieving tool 1 in the wash-over pipe at the surface of the well and prior to running the combined washing and retrieving tool in the well, the retrieving tool unit is preferably disposed in the washover pipe so that the lower end will extend from one end of the section of the wash-over pipe. The mandrell' 5' may be held against rotation by suitable tongs (not shown). In this manner, rotation of the wash-over pipe 80 will cause rotation of the slip cage 29 through engagement of the friction dogs 21 with the wash-over pipe, thereby moving the bushing 10 downward on the left hand threads 9 until the tapered faces 50 of the bushing 10 come in contact with the tapered faces 62 of the slips 51 and start an outward movement of the slips for engagement with the wash-over pipe 80. As the initial outward movement of the slips is begun, the retrieving tool unit 1 may be moved in the wash-over pipe for any desired location therein.

When the tool unit 1 reaches the desired location in a section of the wash-over pipe 80, a vertical upward or picking up movement on the washover pipe 80 will cause the sectional connecting sleeve member 12 and 26 to move vertically upward therewith due to the contact of the friction dogs 21 with the wash'over pipe 80. However, the mandrel 5 and the slip cage 29 will not move upwardly, but will remain stationary until the latches 31 provided in the sleeve 26 have been moved upwardly into contact with the inclined grooves 56, whereby a continued upward movement of the wash-over pipe 80 and sleeve 26 will cause the latches 3-1 to carry and move the cage 29 upwardly into contact with the tapered faces of the bushing and forcing the slips outwardly into engagement with the wall of the wash-over pipe. In this operation, the retrieving tool 1 will be suspended in the wash-over pipe in partially locked condition, such as shown in FIG. 10.

A more positive locking engagement between the retrieving tool 1 and the wash-over pipe 80 through engagement of the slips 51 will permit a tighter connection with the lost fish 97. In order to obtain a better slip bite, a suitable square shaped wrench 74 (FIG. 2) adapted to fit in the equally spaced key ways 73 in the bottom end of the sub 7 is inserted therein, and rotation of the sub 7 in a left hand direction will cause the mandrel 5 to rotate in the bushing 10 held stationary by the wedging action of the tapered faces 50 and 62, and key 60 in key way 59, whereupon the left hand rotation of the mandrel 5 will force the bushing 10 to travel further downwardly or to make up on the left hand threads 9 more completely, thereby moving the slips 51 outward and into a more firmer locking engagement with the inner wall of the wash-over pipe 80. Disengagement of the sub 7 from the threads 6 of the mandrel 5 is prevented by the locking key 75. When the retrieving tool 1 is firmly anchored in the wash-over pipe 80 and the uniatching unit 91 is threadedly connected therewith, the complete unit is ready to be run into the well bore in the conventional manner.

Operation The wash-over pipe 80 is run into the well bore 81 (FIG. 11) upon any suitable supporting string of pipe (not shown) and the retrieving tool mechanism 1 is supported therein by the slips 51 in a manner as has been heretofore set forth. As the threads of the pin member 96 approach the top of the stuck fish 97, water or mud circulation forces the sleeve assemblies 12 and 26 in the tool assembly 1 downwardly whereby the force of the springs 33 will be overcome and the shoulder 57 urges the latches 3 1 inwardly and the sleeve 26 telescopes into the slip cage 29 without etfecting the position of the slips 51. In this position, a continued right hand rotation of the wash-over pipe 80 will cause the pin threads 96 to make up in the female box (not shown) of the stuck fish 97. This make up connection can be made up to whatever tightness the retrieving tool 1 was made up in the wash-over pipe 80 as has been heretofore explained. The firm engagement of the slips with the washover pipe by rotation of the mandrel 5 as hereinbefore set forth, is to permit a tighter make up for the retrieving tool 1 with the lost fish 97 and it is dependent upon the tightness of the left hand threads 9 between the mandrel 5 and the movable housing 10. 7

During the lowering movement of the unit into the well bore and prior to the connection with the lost fish 97, the unlatching means 91 is prevented from any movement or distortive action due to the fact that the male lugs 112 and 113 are provided with aligned apertures 114 and 115 (FIG. 9) cooperating with aligned apertures 116 and 117 in the lower body portion 103 of the inner sleeve. Diametrically opposed brass rivets 118 and 119 are disposed in the aligned apertures, thereby maintaining a non-operative function of the unlatching unit 91 during the lowering of the tool into the well bore. As soon as the pin 96 is threaded into the box of the lost fish 97 and an upward pull on the wash-over pipe with a. simultaneous upward pull on the housings 92 and 93, the pins 118 and 119 will shear, thereby placing the unlatch-ing means 91 or safety joint in readiness for operation.

A continued right hand rotation of the combination wash-over pipe 8%), retrieving tool 1 and unlatching unit 91 will cause the bushing 10 to travel vertically upward on the left hand threads 9 to cause an unthreading of the bushing 10 until an upper shoulder 83 contacts the outward flange 8 provided on the mandrel 5 (FIG. 10) hereby placing the retrieving tool 1. in 21 released position relative to the wash-over pipe 80. The wash-over pipe is provided with any suitable reamer 84 connected thereto at 85. The reamer is provided with teeth 86 for reaming the well bore 81 as is well known in the art. With the bushing 10; moved upwardly, thereby moving the tapered faces 50 away from the tapers 62 of the slips 51, the slips are then automatically disengaged from the inner periphery of the wash-over pipe 80 by the springs 68. In this released condition, a slow movement upward of the wash-over pipe 80 will cause the friction dogs 21 which are frictionally gripping the inner wall of the wash-over pipe 30 to provide a simultaneous movement upward of the sleeve 12 and its connecting lower sleeve 26, which in turn picks up the slip cage 29 through the operation of the latches 31 as hereinbefore set forth, thereby moving the slips 51 outwardly into an engagement with the inner wall of the wash-over pipe so that rotation of the wash-over pipe in a right hand direction, the threads 96 may be further connected with the stuck fish 97 as tightly as desired. Upon release of the right hand torque, and a downward movement of the washover pipe 80, the slips 5-1 are moved downward away from the tapered faces 50, thereby placing the Wash-over pipe in a released position for the wash-over operation in the well bore, such as shown in FIG. 12.

During the setting of the slips 51 with the wash-over pipe 80, the male lug or spline 112 is positioned in the uppermost portion of the pocket 111 as shown in FIG. 13. Upon release of the slips 51 from the wash-over pipe to permit the wash-overoperation, the male lug 112 is lowered into the pocket 104. As previously set forth, for purposes of clarity, only one of the spline operations shall be explained. At all times during the wash-over operation and the downward movement of the wash-over pipe 80, the male flange or spline 112 is positioned in the lower pocket 104, thereby assuring that the unit 91 will be in locked position.

If it is desired to remove the retrieving tool and the wash-over pipe for any purpose, it is only necessary to reengage the slips withvthe wash-over pipe in the manner heretofore set forth, whereby the male lug or flange 112 is moved in an upward direction into the recess 111. After setting the slips, the wash-over pipe and the connected retrieving tool with the outer housing 92 are moved vertically downward to place the male spline 112 in communication with the passageway 110, whereupon a left hand rotation of the wash-over pipe will move the male spline 112 into the passageway 109, so that with vertical movement upward, the wash-over pipe and the retrieving tool will be completely unlatched from the stuck fish 97. In repositioning the wash-over pipe 80 and retrieving tool 1 again in the well bore, the slips 51 are maintained in engagement with the wash-over pipe 80, and as the male spline 112 on the upper body 92 of the unlatching unit 91 approaches the female splines 100, the male spline 112' is caused to contact the upper taper 107 which provides for automatic right hand rotation there- 9 of and directs the. male spline 112 into the groove 109, passageway 110 and into the lower recess 104. As the wash-over pipe 80 is then moved downwardly to release the slips 51 from the tapered portion 50 of the bushing 10 to again start the wash-over operation, the lug .112 is disposed in the lower recess 104 and remains in this position at all times during the wash-over operation, or until the fish is loosened as will be hereinafter set forth.

The unlatching mechanism 91 permits a progressive removal of the stuck fish during the wash-over operation in that after completing a wash-over for any desired number of feet downward from the point of connection with the pin '90, such as where two or more sections of drill collars have been reamed out and washed over, these sections may be removed without removal of the remaining portions of the stuck. collars. In removing the wash-over pipe, retrieving tool, unlatching unit, and a portion of the loosened collars, the wash-over pipe is moved vertically upward to set the slips as heretofore set forth, and in addition, move the male spline 112 from the lower recess 104 to the top recess 111. In this position, a left hand rotative torque is placed on the wash-overpipe and maintained. A string shot can be disposed in the well bore substantially adjacent the threaded joint of the loosened collar where it is desired to break off, and with the left hand torque on the complete string, as soon as the dynamite blast from the string shot is discharged, the vibration therefrom in conjunction with the maintained left hand torque will cause the joint to loosen and permit unthreading thereof so that the wash-over pipe, retrieving tool, unlatching means and desired sections of washed over drill collar may be removed from the well bore. The string shot method of loosening connected joints of threaded strings of pipe in a well casing is conventional in the art and forms no part of this invention. In the back off operation, the retrieving tool is lifted up and rotated to the left which operation causes the slips 51 to tighten against the inner periphery of the washover pipe 80. This tightening is effected by rotation by the fiat surfaces 50 of the hexagon shaped bushing 10 against the flat faces 62 of the slips 51. In FIG. 13 the male lug 112 depicted in dotted lines is to show the position of the lug 112 in slot 109 for a disconnection of the unlatching means.

As the wash-over pipe 80 and its attendant reamer 84 move progressively downwardly in the well bore 81, it may become necessary to add additional strings of pipe before the well bore is reamed sufiiciently to loosen the stuck fish 97. In some instances, the fish may be stuck in the bore through several hundred feet of strata. In order to complete the washing and reaming operation, it is necessary to move the wash-over tool downwardly through the bore a sufficient distance to loosen the stuck fish. -It will be understood as the washing operation continues that the retrieving tool 1 is in released condition relative to the wash-over pipe 80. Furthermore, since the tool is made up with the fish 97, it is in a stationary condition as long as the fish is stuck or until the fish 97 is loosened by the reaming operation.

In order to add the additional sections of pipe string supporting the wash-over pipe 80, it is not necessary to lock the retrieving tool 1 in the released position, but it is only necessary to move the wash-over pipe 80 vertically upward with a simultaneous increase on the pump pressure at the surface of the well, whereupon the increased pump pressure will provide a suflicient fluid pressure exerted on the flow restriction members 14 which is greater than the friction caused by the friction blocks 21 engaging the wash-over pipe 80, thereby permitting movement of the wash-over pipe 80 in a vertically upward movement without movement of the sleeves 12, 26 and attendant cooperating elements, such prevents the slips 51 from moving upward and into contact with the tapered faces 50 for any possible engagement with the inner periphery of the upwardly moving wash-over pipe 80. This increased pump pressure will still permit the mandrel to move Y 10 down with the fish during the above operation and in turn moves the bushing 10 downwardly which sets the slips 51 to the wash-over pipe, so regardless of any operation, the fish 97' is prevented from falling downwardly in the bore any'substantial distance at all times. When the additional string of pipe has been added to the wash-over string, it is only necessary to move the wash-over pipe 80 vertically downward and resume the wash-over operation.

It has been found that in some instances of pump failure that the fluid pressure cannot be increased sufficiently to overcome the frictional engagement of the dogs 21 during a vertical upward movement of the wash-over pipe 80 and in such instances, in order to maintain a free wheeling of the vertical movement of the wash-over pipe 80, it is only necessary to rotate the wash-over pipe 80 in a left hand direction whereupon the sleeves 12 and 26 will also rotate with the wash-over pipe 80 due to the frictional contact of the dogs 21. In this left hand rotation, the cam lock 37 carried in the cut away recess 36 of the sleeve 26 will rotate in the same direction as the sleeve 26 (FIG. 5) until the locking tooth 44 on the cam 37 is brought into engagement with one of the longitudinal key ways 11 provided circumferentially on the mandrel 5. The mandrel 5 being held stationary by connection with the stuck fish will stop further rotation of the cam 37, and the floating pin 43 will be caused to move in the arcuately shaped off-set slot 46 to force the teeth 45 on the inner periphery of the lock 37 into engagement with the outer periphery of the stationary mandrel 5, thereby locking the sleeve 26 with the mandrel 5 and prevent any further movement thereof. In this manner, the sleeves 12 and 26 are prevented from upward movement with the wash-over pipe 80, thereby maintaining the slips 51 in a released condition relative thereto. After addition of the extra section of pipe to the wash-over string,'the wash-over pipe 80 may be rotated in a right hand rotation which will move the pin 43 and cam 37 to permit release of the teeth 45 from the mandrel. The wash-over pipe 80 is then again moved downwardly in its released condition relative to the retrieving tool 1 to continue the washing operation.

It will thus be seen that the present apparatus provides for a free wheeling vertical movement of the wash-over pipe 80 when it is necessary to add extra sections to the pipe string for continued downward reaming. The resilient packer members 14 provide the necessary hydraulic pressure to preclude movement of the sleeves 12 and 26 and any outward movement of the slips 51. However, if such fluid pressure is not sufficient, it is not necessary to yo-yo the wash-over pipe string for cooperation with a suitable locking unit such as J-slot sleeve or the like for locking the sleeves 12 and 26 and the slips 51 to maintain them in a released position from the wash-over pipe, since a left hand rotation of the wash-over pipe will lock the. sleeves 12 and 26 by the locking cam 37 as has been heretofore set forth.

As the wash-over operation continues and the fish 97 is washed and reamed loose and starts to fall, the retrieving tool 1 will prevent the fish 97 from any downward falling by automatically catching the loosened fish 97.

As the loosened fish 97 starts to move downwardly, the connected mandrel 5 will move downwardly simultaneous with the loosened fish 97, however, the sleeves 12 and 26 will remain stationary in the wash-over pipe 80 due to frictional engagement of the dogs 21 as has been hereinbefore set forth. Furthermore, resistance to downward movement of the sleeve 12 is also offered by the flow restriction members 14 acting against the fluid in the annulus 86 between the retrieving tool 1 and the inner periphery of the wash-over pipe 80 and the annulus 87 between the wash-over pipe 80 and the well bore 81. It being understood that the circulating fluid is present in the tool and discharges from: the apertures 70 of the lower sub 7 around the reamer 84 and into the annulus 87, As

the loosened fish starts to fall, the connected retrieving tool and fish act as a piston to create a resistance of the fluid pressure in the annulus. I

The flow restriction gaskets 14 as clearly shown in FIGS. 4 and 15 are preferably any suitable rubber packing material, but not limited thereto, and are molded in the metal ring members 14a in order to fit between the holding rings15 and 16. These restriction gaskets have to be replaced many times because of wear, and also because of insertion of the retrieving tool in larger size wash-over pipes for various sizes of well bores. The circular gaskets are split as clearly shown in FIGS. 15 and 16 and the rings 14a are provided with beveled shoulders cooperating with the bevels on the rings 15 and 16. In order to replace the rings 14a, it is only necessary to unthread the nut 8 suffioiently to loosen up the metal portions 14a relative to the intermediate rings permitting the semi-circular gaskets to be removed and 1 replaced with new ones. In this manner, the speed of the assembly of this portion of the tool is facilitated for replacement of these wearable parts without a complete knoclodown or unthreading of the major sleeve portions of the tool.

The slips 51 are engaged with the wash-over pipe 80 substantially instantaneous with the loosening of the stuck fish and the fish drops only a very few inches to provide a biting engagement and prevent any further dropping of the loosened fish to the bottom of the well bore, In this condition, the loosened fish is ready to be removed from the well bore along with the combination washing unit.

In order to preclude an expensive stripping operation of the complete unit, the removal of the loosened fish may be accomplished by moving the wash-over pipe 80 out of the well bore in any suitable manner until the section of the wash-over pipe Stl in which the retrieving tool 1 is anchored has reached the surface of the well. The wash-over pipe is then held by any suitable holding device, such as slips or the like (not shown), and then a letting in string of pipe 89' is made up securely in the top of the upper bushing Z of the retrieving unit 1, A pick up, or upward movement of the drill pipe 89 will simultaneously move the mandrel 5 upwardly, moving the bushing and its complementary tapered faces 5'0 away from the tapered faces 62 letting the slips recede, thereby releasing the tool unit 1 from the wash-over pipe 30. A right hand rotation of the drill string 89 will rotate the mandrel 5 simultaneously until one of the grooves 11 comes into contact with the pointed boss 4-4 on the rolling lock member 37, thereby causing movement or rotation of the rolling lock member 37 simultaneous with rotation of the mandrel 5. Since the sleeve 26 is held firm with the wash-over pipe 80 by the friction dogs 21, the rotation of the lock member 37 and its finating pin 43 will remain stationary in the moving arcuate slot 46 until the lock cam 37 is forced inwardly to engage the teeth 45 against the outer periphery of the mandrel.

It will thus be seen that the continued right hand ro-. tation of the string 89 and mandrel 5 Will tend to tighten the member 37 against the mandrel 5, thereby preventing the sleeve 26 from moving upwardly and causing engagement of the slips 51 against the wash-over pipe as the tool is lowered in the wash-over pipe. With the tool in this position, it is lowered to the lowermost section of the wash-over pipe 80 (FIG. 14) where a left hand rotation of the drill pipe 89 and mandrel 5 will cause the floating pin 43 to resume its original position and unlock the member 37 and permit the cage 29 to move downwardly as the drill pipe is moved downwardly with the sleeves 12 and 26 remaining stationary until the latch 31 comes in contact with the downwardly tapered face 5 7. At this point, the slip cage 29 is stationary, whereas the mandrel 5 and bushing 10 continue downwardly until the tapered faces 50 and 62 force the slips 51 outwardly 12 into contact with the wash-over pipe 80. Any F ontinued downward movement of the drill pipe 89 will set the slips 51 firmly in the wash-over pipe thus leaving the tool 1 and fish 9'7 suspended in the lowermost section of wash-over pipe 80 (FIG. 13).

The drill pipe 89 is then unthreaded from the upper bushing 2 and removed from the wash-over pipe 80. The upper sections of the wash-over pipe 80 are removed from the well bore until the last joint or section is reached, from which the fish 97 will be extending. The fish 97 is then secured at the surface of the Well with any suitable holding device, such as slips on a rotary table or the like (not shown), and after securement, the wash-over pipe 80 is moved downwardly for a release from the retrieving tool 1. After release, a rotation in a left hand direction will cause the lock member 37 to re-engage the mandrel 5 as hereinbefore set forth to prevent any engagement of the slips 51, thereby permitting the wash-over pipe 80 to be removed from the tool and leaving the retrieving tool made up in the top of the fish 97. The tool unit 1 and the sub member 7 may be unthreaded from the fish with removal of the fish in any conventional manner.

Referring further to FIG. 12 depicting the apparatus during the reaming operation, a short length for the man drel between the sub 2 and the nut 18 is shown, however, this length or distance is usually greater than that shown since the sleeve 12 and assembled parts are telescoped downwardly during the wash-over operation by the mud pressure against the rubber rings 14'. This greater length orspacing permits the wash-over pipe to be vertically reciprocated in order to free the reaming shoe 84 if it should become worn or stuck due to excessive binding.

Alluding further to the progressive removal of the loosened drill collar sections, the hexagon shaped bushing 10 of the retrieving unit cooperating with the flat faces of the slips 51 will permit a tighter gripping action between the slips when it is desired to back off for any purpose by merely lifting up and rotating the wash-over pipe either to the right or left. When the unit is pulled up, the male spline 112 is moved into the slot 111 and rotation either to the right or left will not move the spline 112 out of the slot 111, but the plurality of tapered faces on the hexagon shaped bushing 10 will provide for a tightening of the slips with the wash-over pipe to assist the loosening of the connected joints as has been heretofore explained.

From the foregoing, it will be apparent that the present invention provides for an efficient recovery of drill collars and the like which have been stuck in a well bore off the bottom thereof, The apparatus provides for a washing around the stuck portion of the drill collar with a wash-over pipe and reamer having a retrieving tool dis posed in the lower end thereof and engaging the upper end of the stuck collar so that when it is washed free and becomes loosened, the drill collar is prevented from falling to the bottom of the well by engaging the retrieving tool to the wash-over pipe, after which it may be removed from the well bore, along with the wash-over pipe. The apparatus contemplates a release of the slips for a continued downward movement of the wash-over pipe and its reaming shoe for a complete washing and reaming operation and yet, permits unhindered vertical upward movement of the wash-over pipe for adding extra sections of the pipe string without any re-engagement of the slips during the vertical upward movement by Cf:- fecting a locking of the slips in a released condition through a left hand rotation of the wash-over pipe.

Furthermore, the present invention contemplates that once the retrieving tool has been made up or connected to the lost drill collar, it can be unlatched therefrom and removed from the well bore with the wash-over pipe for any desired purpose. The removed retrieving tool may be replaced in the well bore and again latched with a fish without the necessity of a second make up connection. The unlatching unit permits a progressive re- 13 moval of washed-over sections of lost collars, particularly where considerable lengths or sections of collars are stuck in the Well bore.

Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modification in the precise embodiment of the invention may be made within the scope of the following claims without departing from the spirit of the invention.

I claim:

1. In a wash-over apparatus for retrieving a stuck fish in a well bore comprising a wash-over pipe having a retrieving unit adapted to be positioned therein, said unit comprising an elongated mandrel having a slidable sleeve thereon, a slip cage slidably disposed on the mandrel below the sleeve and telescopically arranged therewith, a plurality of circumferentially spaced slips carried by the slip cage and alternately operable to gripping or non-gripping engagement with the Wash-over pipe, a tapered coupling carried by the mandrel, means cooperating between the mandrel and the coupling and responsive to the rotation of the mandrel in one direction to move the coupling in a direction to engage said slips and to provide a radial outward movement thereof into engagement with the wash-over pipe, means connected to the retrieving unit for a make up connection with th stuck fish, said means comprising an unlatching mechanism carried by the retrieving unit and separable to permit removal of the retrieving unit with the wash-over pipe from the well bore without disturbing the make up connection with the stuck fish, friction means carried by the slidable sleeve and engageable with the wash-over pipe to provide for simultaneous movement therewith, the wash-over pipe movable in an upward direction to actuate the slips carried by the slip cage into a gripping engagement with the pipe and thereby connect the washover pipe to the retrieving unit for permitting separation of the unlatching mechanism, means carried by the slidable sleeve and responsive to rotation of the sleeve with the rotation of the wash-over pipe in one direction to lock the sleeve against the mandrel and prevent movement of the sleeve upon a simultaneousmovement of the wash-over pipe.

2. In a wash-over apparatus for retrieving a stuck fish in a well bore comprising a wash-over pipe having a retrieving unit adapted to be positioned therein, said unit comprising an elongated mandrel having a slidable sleeve thereon, a slip cage slidably disposed on the mandrel below the sleeve and telescopically arranged therewith, a plurality of circumferentially spaced slips carried by the slip cage and alternately operable to a gripping or nongripping engagement with the wash-over pipe, a tapered coupling carried by the mandrel, means cooperating between the mandrel and the coupling and responsiveto the rotation of the mandrel in one direction to move the coupling in a direction to engage the slips and to provide for radial outward movement thereof into engagement with the wash-over pipe, means connected to the retrieving unit for a make up connection with the stuck fish, said means comprising an unlatching mechanism carried by the retrieving unit and separable to permit removal of the retrieving unit with the wash-over pipe from the Well bore without disturbing the make up connection with the stuck fish, said wash-over pipe movable in a downward direction to release the slips from engagement with the wash-over pipe after the make up with the fish, the wash-over pipe movable in an upward direction to operate the slips into a gripping engagement therewith and thereby connect the wash-over pipe to the retrieving unit for permitting separation of the unlatching mechanism, means carried by the slidable sleeve and responsive to rotation of the wash-over pipe in one direction to maintain the slips in disengagement during any upward vertical movementof the wash-over pipe, said tapered coupling responsive to a downward movement of the mandrel upon loosening of the stuck fish provide for an automatic engagement of the slips with the wash-over pipe to catch the loosened fish.

3. In a wash-over apparatus for retrieving a stuck fish in a well bore comprising a wash-over pipe having a retrieving unit adapted to be positioned therein, said unit comprising an elongated mandrel having a slidable sleeve thereon, a slip cage slidably disposed on the mandrel below the sleeve and telescopically arranged therewith, a plurality of circumferentially spaced slips carried by the slip cage and alternately operable to a gripping or nongripping engagement with the wash-over pipe, a tapered coupling carried by the mandrel, left hand thread means cooperating between the mandrel and the coupling and responsive to the rotation of the mandrel in one direction to move the coupling in a direction to engage the slips and to provide for radial outward movement of the slips into engagement with the wash-over pipe, means connected to the retrieving unit for a make up connec: tion with the stuck fish, said means comprising an unlatching mechanism carried by the retrieving unit and separable to permit removal of the retrieving unit with the wash-over pipe from the well bore without disturbing the make up connection with the stuck fish, friction means carried by the slidable sleeve and engageable with the wash-over pipe to provide for simultaneous movement therewith, said wash-over pipe movable in a downward direction to release the slips from engagement with the wash-over pipe after the make up connection with the fish, a recess provided in the slidable sleeve, the wash-over pipe movable in an upward direction to actuate the slips into engagement therewith and thereby connect the Wash-over pipe to the retrieving unit for permitting separation of the unlatching mechanism, a slotted lock member carried in the recess and rotatable with the sleeve, means on the mandrel to limit rotation of the lock member upon rotation of the sleeve, a pin carried by the sleeve and extending through the slotted member and responsive to rotation of the sleeve to move the lock member radially into locking engagement with the mandrel and prevent movement of the sleeve with vertical upward movement of the wash-over pipe.

4. in a wash-over apparatus for retrieving a stuck fish in a well bore comprising a wash-over pipe having a retrieving unit adapted to be positioned therein, said unit comprising an elongated mandrel having a slidable sleeve thereon, a slip cage slidably disposed on the mandrel below the sleeve and telescopically arranged therewith, a plurality of circumferentially spaced slips carried by the slip cage and alternately operable to a gripping or nongripping engagement with the wash-over pipe, a tapered coupling carried by the mandrel, left hand thread means cooperating between the mandrel and the coupling and responsive-to the rotation of the mandrel in one direction to move the coupling in a direction to engage the slips and to provide for radial outward movement of the slips into engagement with the wash-over pipe, means connected to the retrieving unit for a make up connection with the stuck fish, said means comprising an unlatching mechanism carried by the retrieving unit and separable to permit removal of the retrieving unit with the wash-over pipe from the well bore without disturbing the make up connection with the stuck fish, friction means carried by the slidable sleeve and engageable with the wash-over pipe to provide for simultaneous movement therewith, the wash-over pipe movable in an upward direction to connect the retrieving unit therewith and permit separation of the unlatching mechanism, said wash-over pipe movable in a downward direction for cooperating with the tapered coupling to release the slips from engagement with the wash-over pipe after the make up connection with the fish, spline means cooperating between the make up means and the wash-over pipe whereby said wash-over pipe is movable in a vertical upward direction to permit insertion of additional sections of pipe string for continuing the downward direction of the washover pipe, means to maintain release of the slips during the vertical upward movement of the wash-over pipe, said means comprising a recess provided in the slidable sleeve, an arcuately shaped lock member carried in the recess and rotatable with the sleeve, a pointed boss on the sleeve adapted to cooperate with means on the mandrel to limit rotation of the lock member upon rotation of the sleeve in one direction, an arcuate slot provided in the lock member and oif-set relative to the longitudinal axis of the sleeve member, a pin carried by the sleeve and extending through the slot member and responsive to rotation of the sleeve to bear against the walls of the off-set slot to move the lock member radially into locking engagement with the mandrel and prevent movement of the sleeve simultaneous with vertical upward movement of the wash-over pipe whereby the slips are maintained in 2. released engagement therewith,

5. In a wash-over apparatus for retrieving a stuck fish in a well bore comprising a wash-over pipe having a retrieving unit adapted to be positioned therein, said unit comprising an elongated mandrel having a slidable sleeve thereon, a slip cage slidably disposed on the mandrel below the sleeve and telescopically arranged therewith, a plurality of circumferentially spaced slips carried by the slip cage and alternately operable to a gripping or non-gripping engagement with the wash-over pipe, a tapered coupling carried by the mandrel, means cooperating between the mandrel and the coupling and responsive to the rotation of the mandrel in one direction to move the coupling in a direction to contact the slips and to provide for radial outward movement of the slips into engagement with the wash-over pipe, safety joint means connected to the retrieving unit to provide a make up connection with a stuck fish, said safety joint means comprising an outer housing and an inner housing having cooperating spline means to permit disengagement therebetween, said spline means comprising a plurality of lugs provided on the outer housing, a plurality of J-slots provided on the inner housing each having one end open for receiving one of the lugs therein, said lugs and J-slots cooperating in one position therebetween for maintaining the outer housing and inner housing in locked position, said lugs responsive to a movement of the wash-over pipe and cooperating in a second position with respect to the I-slots to permit longitudinal movement of the outer jacket relative to the inner body for disengagement thereof to permit removal of the retrieving tool with the wash-over pipe from the well bore without disturbing the make up connection with the stuck fish, friction means carried by the slidable sleeve and engageable with the wash-over pipe to. provide for simultaneous movement therewith, the Wash-over pipe movable in an upward direction for connection' of the wash-over pipe to said outer housing for permitting separation of the safety joint means, means carried by the slidable sleeve and responsive to rotation of the sleeve with the rotation of the wash-over pipe in one direction to lock the sleeve against the mandrel and prevent movement of the sleeve upon a simultaneous movement of the wash-over pipe.

6. An apparatus for retrieving drill collars lodged in a well bore comprising a wash-over pipe of a size to be inserted in the bore, a fishing tool unit carried in the lower portion of the wash-over pipe, said fishing tool unit comprising separable make up means to provide a make up connection between the fishing tool unit and the drill collars, and pipe gripping means for engagement with the pipe, said gripping means including tapered coupling means operably responsive to downward movement of the wash-over pipe after the make up means has been connected to the drill collars 'for maintaining the gripping means in a non-engaged position with the wash-over pipe to permit continued downward movement of the wash-over pipe substantially below the make up connection, said tapered coupling means also responsive to downward movement of the make up means and drill collars relative to the wash-over pipe for moving the gripping means into engagement with the washover pipe, said make up means including an unlatching mechanism permitting separation thereof for removal of the fishing tool unit with the wash-over pipe from the well bore without disturbing the make up connection with the drill collars, and said wash-over pipe movable in an upward direction to connect the pipe to the fishing tool unit for permitting separation of the unlatching mechanism.

7. In an apparatus for retrieving stuck drill collars in a well bore comprising in combination a drill string r having a Wash-over pipe carried at the lower end thereof, a reamer shoe on the wash-over pipe and a fish retrieving mechanism carried in the wash-over pipe, said fish retrieving mechanism comprising an elongated mandrel, slip means carried by the mandrel for providing engagement of the fish retrieving mechanism with th wash-over pipe during a lowering of the wash-over pipe into the well bore, separable make up means connected to said mandrel providing a make up connection with the stuck drill collars, said make up means including cooperating male and female splines operable in one position therebetween to permit separation of the splines and removal of the fish retrieving mechanism from the well with the wash-over pipe without disturbing the make up connection with the drill collars, the wash-over pipe movable in an upward direction for a connection thereof to the fish retrieving mechanism thereby permitting separation of the make up means, means providing for disengagement of the slip means from the washover pipe during the reaming operation of the reaming shoe around the stuck drill collars and responsive to movement of the drill collars upon loosening thereof to cause a substantially contemporaneous re-engagement of the slip means with the wash-over pipe with the loosening of the collars.

8. In a wash-over apparatus for retrieving a stuck fish in a well bore comprising a wash-over pipe having a retrieving unit adapted to be positioned therein, said unit comprising an elongated mandrel having a slidable sleeve thereon, a slip cage slidably disposed on the mandrel below the sleeve and telescopically arranged therewith, a; plurality of circumferentially spaced slips carried by the slip cage and alternately operable to a gripping or nongripping engagement with the wash-over pipe, a tapered coupling carried by the mandrel, means cooperating between the mandrel and coupling and responsive to rotation of the mandrel to move the coupling in a direction to engage the slips and provide radial outward movement of the slips into engagement with the wash-over pipe, said means responsive to a pull up position of the retrieving unit with a simultaneous rotation thereof in one direction to provide an increased engagement of the slips with the wash-over pipe, and make up means connected to the mandrel for engagement with the stuck fish.

9. In a wash-over apparatus for retrieving a stuck fish in a well bore comprising a wash-over pipe having a retrieving unit adapted to be positioned therein, said unit comprising an elongated mandrel having a slidable sleeve thereon, a slip cage slidably disposed on the mandrel below the sleeve and telescopically arranged therewith, a plurality of circumferentially spaced slips carried by the slip cage and alternately operable to a gripping or nongripping engagement with the wash-over pipe, a tapered coupling carried by the mandrel, means cooperating between the mandrel and the coupling and responsive to rotation of the mandrel to move the coupling in a direction to provide contact with said slips andradral outward movement of the slips into engagement with the wash-over pipe, said means responsive to a pull up post- 17 tion of the retrieving unit with a simultaneous rotation thereof in one direction to provide an increased engagement of the slips with the wash-over pipe, said retrieving unit having means for connection with the stuck fish, said slips having spring biased means operably responsive to downward movement of the wash-over pipe after connection of the retrieving unit with the drill collars for maintaining the slips in released position to permit continued downward movement of the Wash-over pipe, said tapered coupling responsive to downward movement of the loosened drill collar relative to the wash-over pipe for engaging and moving the slips into engagement therewith.

References Cited in the file of this patent UNITED STATES PATENTS 2,762,438 Naylor Sept. 11, 1956 2,804,151 Le Bus Aug. 27, '1957 2,817,555 Le Bus Dec. 24, 1957 2,869,644 Brown Jan. 20, 1959 2,879,849 Le Bus Mar. 31, 1959 

